'You Don't Know JS (book series)' 

"This is a series of books diving deep into the core mechanisms of the JavaScript language... 

(c) 2013-2015 Kyle Simpson 

The materials herein are all— 

Creative Commons License 
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. 

Read online (free):— 

Titles... 

 "Up & Going", (ebook format is free) 

 "Scope & Closures", 

 "this & Object Prototypes", 

 "Types & Grammar", 

 "Async & Performance", 

 "ES6 & Beyond" (in production) 

[[https://github.com/getify/You-Dont-Know-JS/blob/master/README.md#you-dont-know-js-book-series|You Don't Know JS]]